WEDNESDAY, Oct. 23 (HealthDay News) -- A longer period of detoxification may be more effective for people being treated for addiction to prescription painkillers called opioids, according to a small new study.

Abuse of prescription opioids such as oxycodone, hydrocodone and hydromorphone is a major public health problem in the United States. The new 12-week study, which included 70 people undergoing outpatient treatment for opioid addiction, was published online Oct. 23 in the journal JAMA Psychiatry.

For the first two weeks, all the patients took buprenorphine, a medication used to treat opioid addiction. They were then randomly assigned to slowly reduce the dose of buprenorphine over one, two or four weeks, followed by treatment with naltrexone, a medication that blocks opioid strength.

Patients in the four-week group were more likely to stop abusing opioids than those in the one-week or two-week groups, according to a journal news release.

The findings suggest that some prescription opioid abusers may respond positively to outpatient treatment with buprenorphine detoxification followed by naltrexone while undergoing behavioral therapy [counseling], study authors wrote.

"Additional controlled studies are needed to better understand the parameters of efficacious treatments for [prescription opioid] dependence, as well as to identify the individuals for whom brief vs. longer-term treatments are warranted," concluded study authors Stacey Sigmon, of the University of Vermont, in Burlington, and colleagues.